Socialist Prime Minister Jose Luis Rodriguez Zapatero included the announcement he would be seeking the amendment in his investiture speech Thursday before the Spanish congress, but he said any change in the law would not apply to the current generation of Spanish royals.
Under current rules, 36-year-old Crown Prince Felipe will occupy the Spanish throne after his father King Juan Carlos I, even though Felipe has two older sisters, Princess Elena, 41, and Princess Cristina, 39.
Once the constitution is amended, however, the succession will follow chronologically, regardless of gender, instead of through the male line.
Members of the public interviewed by Spanish media welcomed the proposed change. They said it would bring the Spanish monarchy up to date.
Meanwhile, in another break with tradition, Prince Felipe is scheduled to marry Spanish television newscaster Letizia Ortiz, a commoner, in May.